Second graders are expected to be fluent with their recall of math facts with sums up to 20. They must also use their knowledge of place value to add and subtract within 100 using various strategies. Subitizing usually starts out small, but over time, according to Douglas Clements (1999), provides "stepping-stones to constructing more sophisticated procedures with larger numbers" (pg. 401). Virtual manipulatives, apps, and SMART Table activities pose a familiar setting for children as they are used to playing games either online or through handheld devices.
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Clements, D. H. (March 1999). "Subitizing: What is it? Why Teach it?" Teaching Children Mathematics. Retrieved from http://gse.buffalo.edu/fas/clements/files/subitizing.pdf